POE is a framework for cooperative, event driven multitasking in Perl.
Other languages have similar frameworks. Python has Twisted. TCL has
"the event loop". 

POE originally was developed as the core of a persistent object server and 
runtime environment. It has evolved into a general purpose multitasking and 
networking framework, encompassing and providing a consistent interface to 
other event loops such as Event and the Tk and Gtk toolkits.
